1. Field of the Invention
The present invention relates to fungicidal compositions or agents which exhibit excellent fungicidal effects and in which there is no risk of pollution being caused thereby; and to a method for the use thereof. More particularly, the present invention relates to fungicidal compositions for agricultural and horticultural use which comprise or consist of fungicidal amount of a angustmycin A or angustmycin C and a carrier for agricultural and horticultural formulation.
2. Description of the Prior Art
The term "fungicidal composition or agent" as used in the present specification and claims, is meant to include a bactericidal composition or agent besides its literal sense.
Various attempt to utilize anbiotics or metabolic products of microorganisms as agricultural and horticultural fungicides have been made hitherto, and as the result, some good results have been obtained. As antibiotics for agricultural and horticultural use, blasticidis S and kasugamycin have been practically used to control rice blast; polymyxin to control alternaria leaf spot of apple, powdery mildew of vegetable plants and sheath blight of rice; validamycin to control sheath blight of rice; novobiocin to control bacterial canker of tomatos; streptomycin for medical use and oxytetracycline to control citrus melanose; and cycloheximide to control downy mildew of onion.
Most of these antibiotics have effect against specific disease causative organisms for agricultural plants and their applying amount per area is small, and their remaining period in crops and soils is relatively short. However, continuous use of these anbiotics in the agricultural and horticultural field has caused the emergence of resistant strains of pathogenic bacteria and countermeasures have become necessary. Also, use of the medically employed antibiotics as agricultural and horticultural fungicides is prohibited or restricted, as seen in the case of chloramphenicol. Therefore, development of a novel agricultural and horticultural fungicides to be used as substitute for the antibiotic chemical used hitherto has been eagerly desired. No antibiotic chemical which is effective particularly against anthracnose, gray mold and bacterial spot of vegetable plants has been developed yet.